Field of Invention
The present invention relates to a spectroscopic analysis device based on Brillouin dynamic grating and its analysis method, which belongs to the technology of spectroscopic analysis.
Description of Related Arts
The key for spectroscopic analysis devices is how to obtain a high optical wavelength resolution. The method of reducing the Brillouin gain bandwidth can obtain a wavelength resolution of 0.064 pm (8 MHz) (Stefan PreuBler, Andrzej Wiatrek, Kambiz Jamshidi, and Thomas Schneider “Ultrahigh-resolution Spectroscopy Based on the Bandwidth Reduction of Stimulated Brillouin,” IEEE Photonics Technology Letters, 23, 1118-1120, 2011). At present, the spectroscopic analysis devices with the highest wavelength resolution for commercial use is the AP204xB series ultra-high resolution optical spectrum analyzer manufactured by APEX Company, which is based on the interference principle between signal and built-in TLS and has a wavelength resolution of only 0.04 pm (5 MHz).
The major spectral elements in spectroscopic analysis devices includes Volume gratings and Fabry-Perot interferometer. Since volume grating is limited by the technological process, the length of grating is limited and limiting the further increase of resolution of the spectroscopic analysis devices. In addition, during the manufacturing process of volume gratings, defects in manufacturing also impose a limit to resolution and precision of the spectroscopic analysis devices, and the level of precision can only reach 5 pm-10 pm. The spectroscopic analysis devices which employ Fabry-Perot interferometer as the spectral element are also limited by the actual manufacturing process. Since measuring range and resolution are a pair of contradictory parameters, a high resolution cannot be ensured under a large measuring range condition.